Descriptions of New Species and Genera of Fossils, Collected by Dr. FV Hayden in Nebraska Territory, under the Direction of Lieut. GK Warren, US Topographical Engineer; with Some Remarks on the Tertiary and Cretaceous Formations of the North-West, and the Parallelism of the Latter with Those of Other Portions of the United States and Territoriesv. 9Academy of Natural Sciences117–133
Hayden, F. V. and Meek, F. B. 1857. "Descriptions of New Species and Genera of Fossils, Collected by Dr. FV Hayden in Nebraska Territory, under the Direction of Lieut. GK Warren, US Topographical Engineer; with Some Remarks on the Tertiary and Cretaceous Formations of the North-West, and the Parallelism of the Latter with Those of Other Portions of the United States and Territories." Proceedings of the Academy of Natural Sciences of Philadelphia, 9 117–133.